Polyembryony, Biology

Assignment Help:

Polyembryony

Presence of more than one embryo in a seed is termed polyembryony. The phenomenon, first discovered in orange seeds by Leeuwenhoek (1719), attracted considerable attention because of its potential for application in and horticulture. Polyembryony is broadly classified into simple and multiple, depending on whether the supernumerary arises in one or more embryo sacs in the ovule. Simple polyembryony may be sexual or asexual. In sexual polyembryony embryos may originate from the fertilized egg and synergids, or by budding or cleavage of the polyembryony cells or suspensor of the zygotic embryo.

Asexual embryos are produced within the embryo sac without fertilization. Embryos may also originate from diploid nucellar or integumentary cells of the ode and grow into the embryo sac. These embryos are termed adventive or sporophytic. Multiple polyembryonies involve production of accessory embryos from two or more embryo sacs in the same ovule. For example, in the sea Island cotton, Gossypium barbadense, fertilization of egg in one embryo sac stimulates the induction of embryo from an unfertilized egg in the adjacent embryo sac within the same ovule. Thus, diploid-haploid twin embryos are produced in the seed.


Related Discussions:- Polyembryony

State the term in brief -asconoid sponge, State the term in brief -Asconoid...

State the term in brief -Asconoid sponge? Of the three different sponge architectures, it is the simplest. It comrpsies a central choanocyte lined spongocoel which opens to the

Can we prevent ketoacidosis, Q. Can we prevent ketoacidosis? Normally, ...

Q. Can we prevent ketoacidosis? Normally, while maintaining a good sugar control, there is a very little danger of ketoacidosis. One should test for ketones under the following

Heliozoans - protozoan, Heliozoans - Protozoan Heliozoans are spherica...

Heliozoans - Protozoan Heliozoans are spherical protozoan that occur in the sea or in still bodies of fresh water. They are mainly located in the bottom debris. Fine needle li

Rheumatic heart disease, Rheumatic heart disease was the predisposing cardi...

Rheumatic heart disease was the predisposing cardiac lesion for IE in 20 to 25 per cent. In patients with rheumatic heart disease, endocarditis occurs most frequently on the mitral

Bovine rotavirus diarrhoea, Bovine rotavirus diarrhoea The bovine rota...

Bovine rotavirus diarrhoea The bovine rotavirus is a RNA virus with 11 segments of double stranded RNA belonging to the genus Rotavirus in the family Reoviridae. Rotaviruses c

How do antibody-based tests detect how hiv infection work, Q. How do antibo...

Q. How do antibody-based tests detect how HIV infection works? Subsequent to the infection by the HIV the immune system begins the production of antibodies (primary immune resp

Define formation of healthy food habit - combat from obesity, Define Format...

Define Formation of healthy food habit - combat from obesity? Discarding faulty habits as early as possible. Most food habits formed at this age are for a life time. Special c

Compute how much of the absorbance of the bsa, For a sample containing both...

For a sample containing both protein and nucleic acid, the absorbance measured at a particular wavelength will be the sum of contributions from both types of molecule. Using the pr

Exceptions to the cell theory, Exceptions to the Cell Theory Viruses, ...

Exceptions to the Cell Theory Viruses, however, are not the only exception to the Cell Theory as formulated earlier. This has led scientists to take a much broader view of the

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd